水合作用与pH调控两性离子聚合物刷的相变行为
Hydration and pH regulating phase transition of zwitterionic polymer brushes
李康睿 1李循 2王书恒 2刘彼得 2赵新军 1李九智2
作者信息
- 1. 伊犁师范大学 物理科学与技术学院 新疆凝聚态相变与微结构实验室,伊宁 835000;伊犁师范大学 微纳电传感器技术与仿生器械实验室,伊宁 835000
- 2. 新疆维吾尔自治区人民医院 泌尿外科,乌鲁木齐 830000
- 折叠
摘要
本文基于 Flory-Huggins理论,建立理论模型研究水合作用与 pH调控两性离子聚合物(ZP)刷的相变行为.理论模型考虑 ZP 的水合作用,以及 ZP 刷体系中的静电作用.研究发现,在不同 pH 条件下,ZP 刷的体积分数随着水合作的减弱而的增加.随着 pH 的变化,ZP 刷构象随着水合性转变行为明显改变,这是由于 pH 调控 ZP 链单体带有过多的净电荷(正电荷或负电荷),致使 ZP 链内出现静电排斥导致ZP 刷溶胀.另外,当 ZP 链单体呈现过多的净电荷,会在很大程度上决定 ZP 刷体系静电势,影响 ZP 刷的相变行为.通过考察体系自由能,我们还发现,ZP刷体系自由能呈现了极大值,随着 pH值的变化,自由能呈现的极大值随之改变,由此表明了体系的不稳定性,进而导致 ZP 刷体系发生相变.
Abstract
Based on the Flory-Huggins theory,we built a theoretical model to study the phase transition behav-ior of zwitterionic polymer(ZP)brushes regulated by hydration and pH.The theoretical model takes into account the hydration of ZP,as well as the electrostatic effect in the ZP brush system.We found that the volume fraction of ZP brushes increases with the weakening hydration under different pH conditions.With the change of pH,the conformation of the ZP brush changes significantly with the hydration transition behavior,which is due to the ex-cessive net charge(positive or negative)of the pH-regulated ZP chain segment,which results in electrostatic repulsion within the ZP chain and ZP brush swells.In addition,when the ZP chain segment presents too much net charge,it will largely determine the electrostatic potential of the ZP brush system and affect the phase transi-tion behavior of the ZP brush.By investigating the free energy of the system,we also found that the free energy of the ZP brush system shows a maximum value.With the change of pH value,the maximum value of the free energy shows a change,indicating the instability of the system.And then,this leads to a phase transition in the ZP brush system.
关键词
水合作用与pH/两性离子聚合物(ZP)刷/构象转变Key words
Hydration and pH/Zwitterionic polymer brushes/Switching引用本文复制引用
基金项目
伊犁师范大学提升学科综合实力专项(22XKZY09)
伊犁师范大学"重点学科开放课题"项目(XJZDXKphy202101)
伊犁师范大学"重点学科开放课题"项目(XJZDXKphy202102)
伊犁师范大学"重点学科开放课题"项目(XJZDXKphy202203)
伊犁师范大学"重点学科开放课题"项目(XJZDXKphy202204)
国家自然科学基金(22163011)
出版年
2024
国家科技期刊平台
NSTL
万方数据